1. Technical Field
The present invention relates to clamps, and more particularly, to a clamp for holding an external article, wherein the span of the clamp can be quick adjusted.
2. Description of Related Art
Referring to FIG. 1, a conventional clamp typically has a first clamp jaw 1 and a second clamp jaw 2 for holding an article jointly. The second clamp jaw 2 is extended with a receiving section 3, and the receiving section 3 is provided with an adjusting member 4 having internal threaded. The adjusting member 4 is mounted around a driving screw 5, whose one end is pivotally connected to the first clamp jaw 1, and an opposite end is equipped with a handle 6. Each of the first clamp jaw 1 and the second clamp jaw 2 has its free end equipped with a clamping chunk 7.
By operating the handle 6, the driving screw 5 moves with respect to the adjusting member 4, so that a joint between the driving screw 5 and the first clamp jaw 1 can be drawn toward or away from the adjusting member 4. When the joint and the adjusting member 4 are close to each other, the first clamp jaw 1 and the second clamp jaw 2 are opened to wide the span between the two clamping chunks 7. On the contrary, when the joint and the adjusting member 4 are far from each other, the first clamp jaw 1 is close to the second clamp jaw 2, so the span between the two clamping chunks 7 is shortened. When clamp is operated to clamp an external article, a user has to first operate the handle 6 until the span becomes wider than the article, and then operates the handle 6 reversely to draw the first clamp jaw 1 and second clamp jaw 2 together to hold the article, while the driving screw 5 continuously serves to ensure the clamping force exerted onto the article.
During the foregoing adjustment of the span, the user has to keep operating the handle 6 or the driving screw 5 could not move with respect to the adjusting member 4. However, since each rotation of the driving screw 5 only contributes to a small amount of displacement, in the event that the article is much wider than the initial span of the clamp, adjustment of the span becomes very effort-consuming and time-consuming, making the conventional clamp inconvenient in use.